Testing of microelectronics device and method

ABSTRACT

A device and method to test microelectronic parts to determine whether the parts are compromised by active illumination in a testing fixture within a shielded enclosure by analysis of emission metrics. The testing fixture can include a first layer with a capacitive member and a second layer with a cavity to receive a microelectronic part. A filter in a transmission chain can pass a high power signal to the fixture. A filter in a receving chain can pass a low power signal to the analysis unit.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Contract No. HQ0727-16-P-1619

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTINGCOMPACT DISC APPENDIX

N/A

BACKGROUND OF INVENTION

The detection of counterfeit and trojan microelectronics have beenperformed through methods such as Radio Frequency (RF) emissionanalysis, electric current analysis, x-ray analysis, and visualinspection. Such methods can be readily used to determine overallauthenticity or functionality of the device, but for devices that areauthentic that have been manufactured on the limits of performancespecification, have been degraded through environmental conditions, orhave been reused, these methods have previously not been adequate toidentify potential performance issues.

BRIEF SUMMARY OF INVENTION

The technical problem is to fully assess and characterize amicroelectronic device Part Specimen Under Test (PSUT) to determineauthenticity, whether it has been compromised, and its reliability. Anexample, without intending to limit the types and varieties ofmicroelectronic devices, of a PSUT may be a 74HC04 Hex Inverter in a14-lead PDIP package 0.300″ pin to pin wide, 0.250″ package width byabout 0.750″ package length. Another example may be a MicrochipTechnology AT27C512R-45PU 0.600″ pin to pin wide, EPROM Memory IC28-PDIP 13.5 mm package width×37 mm package length. Another example maybe a MAXIM ICM7218BIQI+LED Driver28-PLCC (11.51″×11.51″). As used inthis application the specimen is meant to include not only the type ormodel that the part is designated, but also the specific specimen ofsuch part designation. This application describes and claims amicroelectronic PSUT assessment device and method with far moreconvenience to the operator, speed and ease of PSUT placement orreplacement than conventional testing. The device of this applicationtypically requires no specialized connecting intermediate apparatus suchas a unique precisely manufactured custom fixture for a PSUT. It alsorequires no direct pin-to-metal electrical contact with the PSUT. Byusing active illumination as a PSUT stimulus source, it is possible toenergize the PSUT without connecting the PSUT to a manufactured customfixture. Such a connection is typically time-consuming. The generalizedfixture of this application may be used with a diverse range of partpackages and pin layout. A further advantage is that the fixture doesnot require an exact pin socket configuration, voltages, currents, orclock inputs at specific pins as configured in a hardware board specificto a PSUT. The time from physical receipt of the PSUT, test setup, andactual test time of the PSUT may be reduced, by a factor of 10× to 100×.

The invention addresses how RF emissions from microelectronic parts anddevices can be analyzed for nonconformance to deduce the reliability ofthe device specimen, using a novel apparatus and methods to energize themicroelectronic PSUT.

The device energizes the microelectronic PSUT indirectly by inducing anelectrical current in the microelectronic PSUT by capacitive coupling.Capacitive coupling is accomplished with a capacitive member, preferablytwo capacitive plates also known as illumination plates that serve as anRF illuminator. The capacitive plates are connected to an RF source andpower amplifier that establishes a dynamic electrical field. The varyingelectrical field then induces a current in the device.

The device has a test fixture in the preferred embodiment that has twoor more layers. The first layer has the capacitive plates that areregistered at a predetermined spacing from each other. The second layerpositioned above the first layer has a cavity to receive the PSUT. Thecavity positions the PSUT at a predetermined distance from thecapacitive plates.

The test fixture is placed within the interior of an RF isolatingenclosure with an integrated antenna to acquire unintendedelectromagnetic emissions due nearly exclusively to the energized PSUT.The shielded enclosure reduces RF electrical noise from externalelectronic sources.

A transmission chain is connected to the capacitive plates. Thetransmission chain has a function generator, signal generator, and RFamplifier that provides the RF power and controls the frequency of RFpower to the capacitive plates.

The integrated antenna is connected to a signal analyzer or analysisunit. The signal analyzer serves two functions. It records the spectraof genuine non-compromised PSUTs to enable the determination of emissionsignature metrics. The signature metrics include spectral analysismeasurements including, but not limited to the spectrum dB as a functionof frequency profile, curve fit, cross modulation frequency peakanalysis, amplitude at frequency position, RF peak shape, spacingbetween RF features, relative frequency or amplitude position, harmonicsfrequency dB height, existence or nonexistence of spectral signatures,and non-harmonically related RF peaks. The RF signature metrics arestored on a memory unit as signature database files.

Preferably, 12 or more multiple frequency regions are analyzed. Thesignal analyzer has at least one channel, but is preferably ismulti-channel to acquire spectral data more rapidly. In differentembodiments the signal analyzer has 2, to 16 channels. The number ofchannels is typically a multiple of 2. The spectral acquisition analysiscan be done from an individual channel, a combination of channels, orall of the channels contemporaneously.

The acquisition of unintended emissions of a PSUT can be repeatedmultiple times. The testing can be run for a predetermined number ofrepetitions or for a predetermined time period. The total spectral datagathered can be analyzed in a reasonable time. Similarly, the analysiscan be over finite separated predetermined regions or analyzed over asingle ultra-wide band typically spanning over 80 MHz. The use ofmultiple runs can be averaged such as non-coherent integration in thefrequency domain to increase the signal to noise ratio of spectralsignature elements.

The baseline representative signature of RF metrics of a known exemplaryPSUT, or group of exemplary parts, is used in the analysis of the PSUT.The signature database containing representative signatures is used todefine parameters for algorithmic analysis of the emission spectra ofthe PSUT. The algorithm parameters allow for identification of anon-conforming test spectrum of a PSUT. The algorithms are described inmore detail in the detailed description of the invention.

The signature analyzer may assess the authenticity, Remaining UsefulLife (RUL), and reliability of microelectronic devices utilizingcollected RF emissions from the device. Authenticity is validated byalgorithmic analysis of emission signature features that are compared toknown features of one or more authentic device specimens previouslydetermined by utilizing manual or automated analysis routines.Reliability of the device specimen will be determined by confirming thatone or more of the emission signatures substantially matches theexpected emission signature within a preestablished range throughsignature metric analysis of the device specimen.

Energizing of the microelectronic PSUT or device by capacitive couplingto its internal electronics, conductive traces, and conductors induceselectrical signals such as RF currents and then evokes correspondingemission features. This produces spectral emissions without the directelectrical connection used in traditional energizing methods. Thisoffers far more convenience to the operator and typically requires nospecialized connecting intermediate apparatus such as a unique preciselymanufactured custom fixture for a part. In certain embodiments this isthe preferred method to generate emission content that can be analyzedfor greater analysis assurance.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a graph illustrating the spectrum feature of peak separation.

FIG. 1B is a graph illustrating the spectrum feature of separationdistance.

FIG. 1C is a graph illustrating the signature frequencies.

FIGS. 2A-2B illustrate block diagrams of an active illumination systemusing illumination from an antenna.

FIG. 3 . is a side view of a device and test fixture using illuminationfrom RF power introduced through capacitive coupling.

FIG. 4 is a diagram of an active illumination system with analysissystem using illumination from RF power introduced thru capacitivecoupling.

FIG. 5A a perspective view of test fixture with the device specimenhaving a pin wired as an output to generate spectra to be evaluated.

FIG. 5B is a perspective view of the test fixture with adjustablelocation capacitive coupled plate for illumination and/or spectralemission capture.

FIG. 5C is a perspective view of the test fixture with the PSUT having adie and clock power and ground attached to pins, said PSUT emitting RFspectral features.

FIG. 5D is a perspective view of the test fixture with multiplecapacitive plates to illuminate multiple regions of the PSUT.

FIG. 6A is a perspective view of a test fixture and PSUT with a ferritecore.

FIG. 6B is a perspective view of a test fixture and two-PSUT, anexemplary known good specimen and a test PSUT with an amplifier andinverted amplifier with a combined output.

FIG. 7 is a partial perspective view of a test fixture.

FIG. 8A is a diagram of the method for analyzing emissions.

FIG. 8B is a diagram of the method for creating exemplary probabilitydensity functions.

DETAILED DESCRIPTION OF INVENTION

The following detailed description is merely exemplary in nature and isnot intended to limit the claimed invention to the described examples oruses of the described examples. As used herein, the words “example” or“illustrative” means “serving as an example, instance, or illustration.”The implementations described below are implementations provided toenable persons skilled in the art to make or use the embodiments of thedisclosure and are not intended to limit the scope of the disclosure orclaims. For purposes of the description herein, the terms “upper”,“lower”, “left”, “rear”, “right”, “front”, “vertical”, “horizontal”,“exterior”, “interior”, and derivatives thereof shall relate to theinvention as oriented in the Figures. Furthermore, there is no intentionto be bound by any expressed or implied theory presented in thepreceding technical field, background, or the following detaileddescription. It is also to be understood that the specific devices andprocesses illustrated in the attached drawings, and described in thefollowing specification, are simply examples of the inventive conceptsdefined in the appended claims. Hence specific dimensions and otherphysical characteristics relating to the examples disclosed herein arenot to be considered as limiting, unless the claims expressly stateotherwise.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but, are merely used by theapplicant to enable a clear and consistent understanding of theinventions. Accordingly, it should be apparent to those skilled in theart that the following description of exemplary embodiments of theinvention are provided for illustration purposes only and not for thepurpose of limiting the invention as defined by the appended claims andtheir equivalents.

It is to be understood that the singular forms “a”, “an”, and “the”includes the plural unless the context clearly dictates otherwise. Thus,for example, reference to “a circuit board” includes reference to one ormore of such circuit board.

It is to be understood that a compromised or modified device specimen,PSUT, or microelectronic refers to a device specimen which has beenmodified to have reduced functionality, has been aged, offers reducedreliability for its intended use, or has been modified for functionalityother than the original manufacturer's intended use of the device. Acompromised or modified device specimen also includes counterfeitdevices that may not function according to the original manufacturer'sintended use or specified operational ranges such as temperature,voltage, power dissipation, or frequency ranges.

It is to be understood that an unmodified PSUT, or microelectronic partincludes a part specimen that has not been modified from its originalmanufacturer's intent in bit, byte, or word patterns in software,firmware, or programmable hardware, or by other changes such as FocusedIon Beam (FIB) circuit editing to alter the devices' functionality. Italso has not been substantially aged beyond the expectations of theuser. Unmodified also means uncompromised.

The forgoing description will be focused on emission of unintendedelectromagnetic energy and, more particularly, the emission ofunintended electromagnetic energy being in a RF spectrum, which istypically referred to in the art as frequencies below 300 GHz, althoughinfrared, infrasonic and other emissions are also contemplated by theexemplary embodiments. They are unintended in the sense that themanufacturer and designer did not intentionally design the device tocreate those emissions and had not originally intended to use thoseemissions. They are derived as unintentional, harmless artifacts of thedesign and manufacture process.

It is to be understood that an unintended electromagnetic emissionsignature, RF signature, spectral signature element, spectral signature,signature element, RF emission signature, or emission signature refersto the frequency domain spectral features that are used herein touniquely identify the hardware and/or software configuration of adevice. An emission signature is comprised of one or more signatureelements that each having one or more of a frequency position,amplitude, phase, and/or shape.

It is to be understood that non-linear attachments, non-linear mixingproducts, or side-band features are comprised of the one or morefrequency domain spectral signature representations of frequency mixingproducts on a carrier frequency. Non-linear attachments can besymmetrically or asymmetrically distributed around a central emissionsignature, with greater or lesser amplitude than the central emissionsignature.

It is to be understood that a non-harmonically related signature elementis one or more signature elements that originates from a differentprocess, computation, electronic component, or subcomponent than areference signature element. The relationship between twonon-harmonically related signature elements can be quantified by one ormore of frequency separation, amplitude, and/or shape.

It is to be understood that an emission signature metric, signaturemetric, or metric refers to the results of algorithms used to uniquelyidentify RF spectral emission signature features. An emission signatureincludes, but is not limited to, the absolute frequency of the signatureelement, the shape of a signature element, the frequency spacing betweensignature elements, the Bessel parameters of non- linear attachments toa signature element, the shape of an envelope formed by non- linearattachments to a signature element, the number of signature elements,and/or the number of non-linear attachments to a signature element. Atypical signature element may be characteristic of one or more spectralpeaks within a spectrum, said spectral peak or peaks with associatedfrequencies, dB levels, shape, or phase noise characteristics. Also, atypical signature element may have characteristics of one or morespectral peaks within a spectrum, said spectral peak or peaks withassociated frequencies, dB levels, shape, or phase noisecharacteristics.

It is to be understood that active illumination, illumination, and RFillumination refers to electromagnetic energy directed at a devicespecimen from an antenna, and/or capacitive plates. The directedelectromagnetic energy is used to energize the PSUT to eliciting anelectromagnetic emission having an RF emission signature.

It is to be understood that a signature database is a collection offiles, lists, or instructions that are unique to specificmicroelectronic parts, devices, and/or components. A signature databasefile, signature file, or metric file contains instructions for one ormore of specific frequencies, frequency ranges, Resolution Band Widths(RBWs), algorithms, algorithm parameters, signal processing parameters,analysis processing instructions for a unique part in order to performsignature metric analysis on unintended RF emissions, and/or probabilitydensity functions (PDFs) of one or more exemplary PSUTs. A signaturefile contains the information needed to acquire spectral emissions thatcan be used to uniquely identify the part or device using signalprocessing and algorithmic solutions to quantify and compare emissionspectra from a PSUT to one or more exemplary PSUTs or devices.

It is to be understood that an algorithmic solution, or algorithmicanalysis is the result from an algorithm that has been processed for aspectral emission signature based on specified algorithm, algorithmparameters, and/or signal processing parameters. An algorithmic solutionis unique to a specified signature metric for a defined spectralemission signature in a specified frequency region of interest.

The emphasis of microelectronic analysis has been on determining theauthenticity of the device specimen, with no emphasis on thedetermination of how well an authentic device will function. Thetechnical problem is to take emission spectral measurements and providerelative reliability assessments of device specimens that have been inlong term storage, reworked by the manufacture, salvaged from otherboards, used under out-of-manufacturer-specified conditions, or reusedfrom other applications. The technical solution is to repeatedly acquireemissions spectra, analyze the distribution of quantitative metrics ofthe spectral features, and compare the distributions to those of knownreliable components. The emission spectra will be generated, measured,and analyzed in a complete system described herein.

The system acquires valuable characteristic features embedded in partssuch as integrated circuits' and other microelectronics' unintended RFemissions. By examining the unintended emissions, it is possible toidentify PSUTs that are counterfeit, damaged, aged extensively,compromised, or operating out of the manufacturers specifiedperformance. PSUTs can also be compromised by physical-cyber andcyber-attacks. By using active illumination, it is possible to energizethe PSUTs without connecting the PSUT to an assembly or subassembly.Connecting the PSUT is typically time-consuming. A more generalengagement permits covering a diverse range of parts package and pinphysical construction may be made without requiring the exact pin socketconfiguration, voltages, and currents at specific pins to be configuredin a hardware board that is specific to the PSUT. Energizing the PSUTwithout connecting it allows for examination of physical or cyberexploits and other compromises in the PSUT that remain dormant duringnominal operational conditions. Trojan, cloaked, or dormant cyberexploits are more difficult to discover than the physical anomalies in aconnected PSUT.

Capacitive plates are used to stimulate the PSUT, contacting thenon-conducting chip top parallel to the plates' surface. The capacitiveplates establish an electrical field that induces a current in theconductors within the die, the circuit components, or the conductiveinterconnects.

Turning to FIG. 1A, Graph 100 illustrates the peak separationprobability distribution of an exemplary uncompromised device 130 andthe peak separation probability distribution of a compromised device 140specimen with a graph of peak frequency separation versus theirrespective probability density functions. The probability densityfunction metric units are shown on the Y-axis in relative terms ofreference. FIG. 1B is a graph 110 illustration of the probabilitydensity function metric of the curve fit results comparison between theuncompromised part 160 and compromised PSUT 150. FIG. 1C graphs 120illustrates an exemplary device's signature element frequency positionmeasurement of the nominal 50 MHz signature element 170 result andPSUT's signature element frequency position measurement of the nominal50 MHz signature element 180 versus their respective probability densityfunction results. These illustrate the probability density versusvarious possible signature metrics. In probability theory, a probabilitydensity function (PDF), or density of a continuous random variable, is afunction whose value at any given sample (or point) in the sample space(the set of possible values taken by the random variable) can beinterpreted as providing a relative likelihood that the value of therandom variable would equal that sample. The PDF provides a usefulmethod of distinguishing distributions of signals. Here the peaks of theemissions are evoked by active illumination. The measurementsillustrated are not limiting to the types of measurements that can beused in the described analysis.

FIG. 2A is a diagram detailing an embodiment of the RF filters in anactive illumination system used to illuminate the PSUT. Reference 200 isthe transmit chain. The transmit chain 200 has a function generator 240connected to a signal generator 235. The function generator 240connected to a signal generator 235 may be comprised in a single unitsuch as a pre-configured Arbitrary Waveform Generator. The signalgenerator 235 is connected to a RF amplifier 230 which is connected toone or more filters 225. Depending on the application, the filters 225can be a band pass filter, a low pass filter or a combination of theband pass and low pass filters. Typically, the filter passes thefundamental frequency and rejects the higher harmonic frequencies. Abandpass filter may be used to only pass the fundamental frequency,rejecting both higher harmonics and sub-harmonics. Typically, thecomponent or IC specimen responds to the fundamental RF illuminationfrequency with unintended emission RF peak features around the 3^(rd)and 5^(th) harmonic. The RF Filter 225 and 265 reduces the emission ofharmonics generated within the RF amp 230 or signal generator 235 frompropagating emission artifacts into the analysis unit 210 andoverwhelming or being mistaken for the desired unintentional emissionsfrom the component or IC PSUT which are typically within the samefrequency range. The RF Filter 225 also reflects and reduces the desiredunintentional emissions from the component or IC specimen frompropagating back into the RF Amp 230 and being attenuated there, thusmaintaining a higher level of signal strength propagating into theReceive Hardware Chain 205. The power output level of the RF amp 230 maybe adjustable as some parts' unintentional emission response atdiffering power levels at differing frequency may vary greatly. Thefrequency of the Signal Gen 235 and filters 225 and 265 may beadjustable to allow illumination at a plurality of frequencies. Thisallows the active illumination a flexibility in energizing the PSUT or avariety of parts tested under various frequencies or waveforms.

FIG. 2B illustrates a receive chain 205 that has a multiplicity of highpass, lowpass, bandpass, or band reject filters 265. The output of thefilters 265 containing low power RF unintended signal emissions 260 fromthe component or subcomponent is connected to the analysis unit 210. TheReceive Hardware Chain 205 also serves to reject and prevent the highpower fundamental frequency from the output of the RF Amp 230 used toilluminate the component or IC PSUT from propagating into the analysisunit 210 and saturating it or damaging it due to the high RF powerlevels present.

FIG. 3 is side view of a testing fixture 300 also known as thecapacitive plate assembly showing capacitive plates used to inducecurrent in the device. Its configuration typically enables the testingof any devices similarly physically dimensioned and constructed, withonly signature data and illumination parameters such as frequency andpower level changing between devices. Capacitive fixture assembly 300has capacitive plates 360 mounted on the base of the assembly. Theplates are preferably parallel and mounted side by side separated at apredetermined distance. Also, the plates can be at a predeterminedangle. An RF input voltage line 350 is connected to the output of thetransmit chain 200. A corresponding RF voltage line 310 may be out ofphase with the RF input voltage line 350 such as 180 degrees out ofphase or may be ground and is connected to the other capacitive plate360. The input and output currents are of substantially opposite phase.The RF current creates an electrical field between the capacitive plates360. The fluctuating electrical field energizes the part 330 that resultin evoked RF emissions 340 from the PSUT 330. A typical RF Illuminationvoltage across the capacitive plates 360 is 1 Volt to 10 Volts,depending on the specifications of the PSUT, the illumination frequency,the thickness of the insulating tape, the dielectric constant of theinsulating tape, and the composition of the device packaging. Anempirical method is recommended to find the optimum voltage value. A 50Ohm RF dummy load 448 may be used at the input to the integrated antennaenclosure 415 to better provide impedance matching for the RF amplifier430.

The capacitive plates 360 may be electrically insulated from the part330. The preferred embodiment is to cover the side of the capacitiveplates 360 nearest the part with an electrically insulating tape 320,preferably an adhesive electrically insulating tape 320. The PSUT 330 isreceived by the test fixture 300 generally near or adjacent to theinsulating tape 320. The tape 320 is not always necessary, as some partssuch as DIP packaged parts may be placed with their non-conducting topsurface upside down on the test fixture 300 and their pins not come inelectrical contact with the capacitive plates 360. This is a typicaltest configuration for such parts. However, the tape prevents damage toa chip if an operator inadvertently places it in the wrong orientation.Some parts have rounded pins on the side, or conductive metal plates onthe top surface necessitating the tape to prevent electrical contactwith the plates 360. When energized by the field generated by thecapacitive plates 360, the PSUT 360 emits an unintended RF emissionanalog signal 340.

FIG. 4 is a block diagram of an embodiment of active illumination of adevice. The device is comprised of the transmit chain 400, an integratedantenna enclosure, 415, a receive hardware chain, 405, and a signalanalysis device, 410.

The transmit chain, 400, has a function generator 420, that is connectedto a signal generator 425, that is connected to an RF amplifier 430 thatis connected to one or more filters 435. Preferably the one or morefilters 435 are one or a combination of a low pass, high pass, andbandpass filters.

The output of one or more filters 435 are connected to capacitive plates445. The capacitive plates 445 are preferably arranged as shown in FIG.3 in capacitive plate assembly 300. The capacitive plate assembly 300 iswithin the integrated antenna enclosure, 415. The capacitive plates 445energize the PSUT 450, which causes electromagnetic emission 460, thatis captured by the integrated antenna enclosure 415.

The receive chain 405 has one or more filters 440. Preferably the one ormore filters are one or more of a high pass, lowpass, bandpass, andband-reject filters. A signal analyzer 410 is connected to the output offilters 440. The receiver and signal analyzer 410 are also referred toas the RF Receiver and Analyzer Unit 410. The receiver is preferably asensitive RF receiver with a sensitivity of −170 dBm.

The signal collection and analysis system 410 is connected to thereceive chain. The signal collection and analysis system has a signatureanalyzer spectrum analyzer, processing unit to compare spectrum metricsto acquired spectrums, and a memory unit for storage of a signaturedatabase. A spectrum analyzer is one type of signature analyzer as usedin this application. In another embodiment the memory unit retains theacquired spectrum. The signature database contains information onspectrum metrics are a suite of metrics such as peak frequencyseparation, peak location distribution, peak frequency and amplitudeseparation distance, degree of curve fit, and spectrum shape. Thespectrum of an uncompromised part, component or subcomponent isinitially acquired and a signature database file is created that resideson the memory unit. The advantage is that the spectrum metrics allow forexamination and comparison of exemplary parts with test PSUTs onmultiple frequency bands and multiple spectrum features for purposes ofcomparison.

FIG. 5A shows an embodiment 500 with the perspective view having aninverted view or upside down view, that is the surface shown withcapacitive plates 505 is facing down on the test fixture 300. The testfixture is not shown, while capacitive plates 505 are shown. Theembodiment 500 has the PSUT 520 generally near or adjacent to thecapacitive plates 505 which are near each other but separated by apredetermined distance. The capacitive plates 505 have input wires 510that carry RF AC voltage that capacitively couples to the PSUT 520. Thisis the sole source of power to energize the PSUT 520.

In FIG. 5B, an embodiment 525 has the PSUT near or adjacent tocapacitive plates 540. Capacitive plates 540, are used for bothstimulation and as antennas while selected PSUT chip pin or pins 530 maybe grounded with wires 535. This may drastically change the current paththrough the chip, exercising its circuitry in a different manner.

The wired connection to the capacitive plates 540 is not shown in FIG.5B. In this embodiment 525, the pins 530 may be connected to ground thepart 520 by wires 535 in order to alter the electrical activity of thePSUT 520. A tomography plate 545 is used for additional spectrumacquisition functioning as an additional antenna input to be analyzed orfor additional RF illumination tomography of the PSUT. The tomographyplate 545 may be connected to an additional separate Transmit Chain 400to selectively illuminate a specific region of the PSUT adjacent orunder it. The additional separate Transmit Chain 400 may illuminate atthe same frequency as the plates 540, at the same frequency but adifferent phase as the plates 540 such as 90 degrees out of phase or 180degrees out of phase, the additional separate Transmit Chain 400 mayilluminate at a different frequency, as the Plates 540. The additionalseparate Transmit Chain 400 may illuminate at a swept frequency range orilluminate with a non-sinusoidal waveform, or a multiple frequencysinusoid-based composite waveform. The additional separate TransmitChain 400 may illuminate with complex signals from an Arbitrary WaveformGenerator, including random or pseudo-random white noise. The tomographyplate 545 is fixed or movable, manually or automatically at location550. Multiple tomography plates 545 as fixed or movable and separatelyperforming as illumination or performing as antennas may also beemployed and is envisioned herein. An additional separate Transmit Chain400 may also illuminate the PSUT at varied power levels while thetomography plate 545 is stationary or moving. The tomography plate 545may be attached to a x,y,z linear position encoder to determine itscurrent position, or may be positioned at an x,y,z coordinate locationmanually or with a linear motion encoder. The motion or position of thetomography plate 545 may be coordinated with an illumination of thetomography plate 545 if the tomography plate 545 is used forillumination, or the motion or position of the tomography plate 545 maybe coordinated with additional spectrum acquisition into a receive chain405 and Signal Collection and Analysis System 410 and functioning as anadditional antenna input 465 to be analyzed. Thus, the illumination ofthe PSUT vs. location or the spectrum acquisition of the PSUT vs.location may be performed.

The tomography plate 545 may share the RF illumination signal withcapacitive plates 540 using a splitter such as a 2-way RF splitter. Thetomography plate 545 may share the Signal Collection and Analysis System410 using splitter such as a 2-way RF splitter.

FIG. 5C shows an embodiment 555 where the pins 530 of the PSUT 575 maybe connected to one or a plurality of wires 570 on one or a plurality ofpins 530 for grounding, for supplying power, for supplying controlvoltages to change chip operational state, for supplying commands to thechip such as SPI bus commands, for supplying test voltages such asanalog voltages into an ADC, or for taking additional measurements suchas time domain voltage measurements. The capacitive plates 560 areconnected by wires 565 to the RF power input from the transmission chainas shown in FIG. 4 and also may be connected to the receive chain 405 RFinput cable 465 which is typically a 50 ohm coaxial cable.

The difference between this embodiment 555 and the embodiment 525 inFIG. 5B is that the embodiment 555 has a view of the orientation of thePSUT 575 from the top of the PSUT 575, as positioned upside down in thetest fixture. In FIG. 5B, the embodiment 525 has the view orientation ofthe part 520 pins are shown in a normal configuration with the PSUTupside down on the test fixture as is typical in normal use. Thecapacitive plates 560 that are used to energize the PSUT 575 can be usedto receive induced electromagnetic emissions from the PSUT 575 and inputinto receive chain 405. A capacitive plate 560 may be used foradditional spectrum acquisition functioning as an additional antennainput to be analyzed or for additional RF illumination tomography of thePSUT.

FIG. 5D shows an embodiment 580 where multiple smaller regionalcapacitive plates 590 are connected to the transmission chain by 585.The multiple capacitive plates 590 are controlled separately to energizedifferent regions of the PSUT 520. The capacitive plates 590 can beselectively operated. Each connected capacitive plate 590 can receiveindependent or dependently controlled AC signals 585. One or more ofcapacitive plates 590 may be connected to an Arbitrary Signal Generatorfor capacitively coupling voltages into specific regions and influencingthe chip circuitry with additional complex stimuli. The advantage ofthis embodiment is that there is a high likelihood of emission spectracontent to include non-harmonically related spectral elements that canprovide additional information regarding part functionality.Additionally, some of the capacitive plates 590 may alternatively serveas antennas for added unintended emission inputs instead of activeillumination plates.

FIG. 6A embodiment 600, a ferrite core 615 focuses inductive RFillumination from the underside of the PSUT 610, the underside of thePSUT not generally adjacent to the illumination plates 605, to inducecurrents that influence interconnect line currents and traces within thechip inductively, separately from an or any capacitive-based currentgeneration. The ferrite core 615 may be connected to the output of anillumination transmit chain 400. The ferrite core 615 induces additionalRF input to regions of the PSUT 610 using H-Field coupling which differsfrom the capacitive coupling resulting from the capacitive plates 605 orthe one or more locally positioned capacitive plates 545. Each connectedferrite core 615 can receive independent or dependently controlled ACsignals 585. One or more of ferrite cores 615 may be connected to anArbitrary Signal Generator for capacitively coupling voltages intospecific regions and influencing the chip circuitry with additionalcomplex stimuli. The advantage of this embodiment is that there is ahigh likelihood of emission spectra content to include non-harmonicallyrelated spectral elements that can provide additional informationregarding part functionality.

FIG. 6B is an embodiment 640 which shows a substantially out of phasereceived signal from exemplary PSUT 620, and a test PSUT 625 causingsome elements of the received signal to cancel out. This serves tocancel out signals in common and allow signal differences arising frompart differences to be more clearly seen. Using an inverting amplifier635 to invert the phase 180 degrees from the exemplary PSUT 620, thepart's 625 signal is combined with the exemplary part's 620 signal, tocancel or substantially reduce common features, lowering the noisefloor, and making algorithmic analysis of spectrum metric differencesmore apparent with a higher signal to noise ratio. Preferably, thisembodiment has two separate Low Noise Amplifiers and antennas in thereceive chains. One of the LNAs being an inverting amplifier 635 and theother 630 not. The exemplary part 620 and the part 625 may beilluminated from one or more sets of capacitive plates. The resultingsingle output signal 640 is propagated to the receive hardware chain. Inthis embodiment, the illuminating capacitive plates may be bothconnected to the RF output from transmit chain 400 and used as antennasto receive the unintended emissions by also being connected to theReceive chain 405. An embodiment wherein the capacitive plates bothilluminate with RF and act as antennas rely on the transmit chain filter435 and receive chain 405 filters to create the needed low dBm levelunintended emissions without passing the high dBm level RF illuminationpower into the Signal Analysis and Collection system 410.

FIG. 7 is an embodiment of the RF capacitive coupling device testfixture. A printed circuit board 750 is populated with an inputconnector 720, leads 710 from the input connector 720 comprising groundand RF leads, and two capacitive plates 740. An insulating guide plate730, is positioned on top of the capacitive plates 740, to receive andregister PSUTs during measurement. The insulating guide plate 730 andthe capacitive plates 740 form a 2-layer test fixture. The insulatingguide plate 730 has a cavity to receive the PSUT. This cavity allows forthe PSUT to be spatially registered in a consistent position relative tothe capacitive plates increasing the consistency of test results. Theinsulating guide plate 730 can be configured for one specific devicepackage or configured, as shown, to accommodate multiple devicepackages. A cutout region 780 may be used to register a PSUT in a Dualin-line package (DIP) accurately. The cutout region 780 accommodatingboth a narrow and wide DIP package is shown therein.

FIG. 8A shows the method of active illumination to induce current flow.Step 800 induces active illumination of the PSUT at the selectedfrequency or frequencies and RF power level or Power levels for thatPSUT. The illumination frequency, power level, and waveform areselectable according to the part geometry and properties. Theillumination frequency, power level, and waveform can be provided to thePSUT in a wide range of combinations. The optimal combination isdetermined when the exemplary part is measured for algorithmic solutionsto signature metrics used by the system. These illumination parametersare dependent on the nominal operating condition of the PSUT, as well asthe geometry of the package type used by the PSUT. These illuminationparameters are specified by the signature database (DB) and provided tothe RF transmit chain, or can be manually input to the RF transmitchain. The signature database also provides one or more frequencies,frequency spans, RBWs, signal processing parameters, algorithms to usefor each region of interest (ROI), algorithmic parameters to be used inemission spectra analysis, and probability density functions (PDFs) ofthe set of one or more exemplary parts.

Step 810 is the acquisition of the emission signature by the analysisunit. The frequency domain RF signature is captured in one or more ROIs(Regions Of Interest) with unique RF metric content as specified by thesignature database file for the unique PSUT.

Step 820 compiles a metric dataset from the algorithms and algorithmicsolutions specified in the signature database file. The algorithmsspecified by the signature database file are analyzed using theparameters specified by the signature database file on a ROI by ROIbasis. The resulting algorithmic solutions are compiled for eachacquisition into an aggregate for each ROI.

Step 830 determines PDFs of the PSUT based on the compiled algorithmicsolutions aggregated in step 820. The kernel density estimatordetermines the PDF for each emission signature metric in each frequencyROI.

Step 840 performs a comparative analysis. The comparative analysiscompares the metric PDF between the one or more exemplary parts and thePSUT for result analysis. Typically, a broadening of the PDF for a givenmetric, i.e. increased standard deviation, indicates reduced reliabilityas there is increased variability in the part's operation. A shift inthe PDF mean or median indicates that there is a change in the part'sperformance or behavior. A change in shape of the PDF typicallyindicates that the metric is multi-modal, and the emission spectra hasmore than one preferred emission signature.

Typically, Step 810 is performed for a set number of acquisitions or fora set duration of time. This can be modified by user input to theanalysis unit. Multiple measurements are used to raise the signal tonoise ratio by combining the acquired signals and to increasestatistical certainty.

The repeated step 810 can be done a fixed number of times, can bearranged to repeat the measurement for a fixed period of time, orrepeated until a certainty threshold has been reached, which isespecially applicable for borderline parts.

FIG. 8B shows the method of creating an exemplary PDF for one or moreexemplary PSUTs. Step 850 consists of one or more of steps to identifyoptimum illumination power, frequency, and/or other test parameters,acquire spectral emission signatures from one or more exemplary PSUTs,the identify of ROIs for signature metric analysis, identify metrics toapply to the emission spectral signature in the identified ROIs,optimize algorithmic parameters for identified metric analysis, creatingone or more files to save hardware and/or software parameters, and/orpropagating one or more hardware and/or software parameter files to thesignal analyzer memory. Step 850 can be performed one or more times tooptimize hardware and/or software parameters for the set of one or moreexemplary PSUTs. Step 850 will be performed for each unique part type,for example for each microelectronic device with a unique National StockNumber (NSN).

Step 860 shows the method of extracting a PSUT metric database. Step 860consists of one or more of steps to collect multiple spectral emissionsignature acquisitions for each ROI identified in step 850 from one ormore exemplary PSUTs, determination of the algorithmic solution for eachacquisition for each identified metric, compilation of aggregatedalgorithmic solutions for each identified metric, and/or compilation ofstatistical parameters of aggregated algorithmic solutions for eachidentified metric. Multiple acquisitions of the spectral emissionsignature for each ROI is required for reliable statistical analysis.Typically, a minimum of thirty (30) acquisitions are required forreliable analysis.

Step 870 shows the method of determining the exemplary part probabilitydensity functions for each metric identified for each ROI identified instep 850. Step 870 consist of one or more of steps to statisticallyanalyze the aggregated algorithmic solutions for each identified metricfor each ROI identified in step 850. The statistical analysis caninclude one or more of the parameters of mean, median, standarddeviation, amplitude, curve fitting parameters, and/or shape of thedistribution.

Step 880 shows the method of saving the exemplary PSUT PDF to thesignature database on the signal analyzer memory. Step 880 consists ofpropagating one or more files containing PDFs, aggregated algorithmicsolutions of one or more metrics, and/or characteristic statisticalclassifiers of aggregated algorithmic solutions of one or more metricsto the memory of the signal analyzer.

Although specific advantages have been enumerated above, variousembodiments may include some, none, or all of the enumerated advantages.Other technical advantages may become readily apparent to one ofordinary skill in the art after review of the following figures anddescription. It should be understood at the outset that, althoughexemplary embodiments are illustrated in the figures and describedbelow, the principles of the present disclosure may be implemented usingany number of techniques, whether currently known or not. The presentdisclosure should in no way be limited to the exemplary implementationsand techniques illustrated in the drawings and described below.

Unless otherwise specifically noted, articles depicted in the drawingsare not necessarily drawn to scale.

Modifications, additions, or omissions may be made to the systems,apparatuses, and methods described herein without departing from thescope of the disclosure. For example, the components of the systems andapparatuses may be integrated or separated. Moreover, the operations ofthe systems and apparatuses disclosed herein may be performed by more,fewer, or other components and the methods described may include more,fewer, or other steps. Additionally, steps may be performed in anysuitable order.

To aid the Patent Office and any readers of any patent issued on thisapplication in interpreting the claims appended hereto, applicants wishto note that they do not intend any of the appended claims or claimelements to invoke 35 U.S.C. 112(f) unless the words “means for” or“step for” are explicitly used in the particular claim.

We claim:
 1. An apparatus, comprising: a testing fixture configured toreceive an electronic part specimen under test (PSUT) and energize thePSUT without a direct pin-to-metal electrical contact with the PSUT; ashielded enclosure having an interior and exterior, the testing fixturepositioned within the interior; a receiving antenna positioned withinthe interior; a transmission chain connected to the testing fixture, thetransmission chain at least including a filter to pass a high powersignal to the testing fixture; a receiving chain connected to thereceiving antenna, the receiving chain at least including a filter topass a low power signal; and an analysis unit connected to the receivingchain to analyze the low power signal, wherein the testing fixturecomprises a capacitive member to capacitively energize the PSUT.
 2. Theapparatus of claim 1, wherein the transmission chain further includes: afunction generator; a signal generator; and a radio frequency (RF)amplifier connected to the signal generator; the filter in thetransmission chain being connected to the RF amplifier.
 3. The apparatusof claim 1, further comprising connections from the PSUT to one or moreof a ground source and a clock source.
 4. The apparatus of claim 1,wherein a processing unit and a memory unit are connected to each otherand to the analysis unit.
 5. The apparatus of claim 1, wherein aprocessing unit and a memory unit are connected to each other and to theanalysis unit, the memory unit storing an RF spectrum signature databaseof one or more uncompromised microelectronic parts and the processingunit having one or more algorithms to validate a presence of emissionspectra of the PSUT in a response to comparison of algorithmic solutionsto metrics evaluated against the emission spectra from the PSUT andreporting whether the PSUT is compromised and/or degraded and/orunreliable.
 6. The apparatus of claim 1, wherein the testing fixturecomprises a first layer having the capacitive member and a second layeradjacent to the first layer with the capacitive member having a cavityto receive the PSUT.
 7. The apparatus of claim 1, wherein the testingfixture comprises: at least one capacitive member having two generallyflat plates positioned at a predetermined distance from each other, eachgenerally flat plate having an upper side and a lower side with ACvoltage supply of an opposite phase connected to each generally flatplate; and an electrical insulator between the two generally flat platesand the PSUT.
 8. The apparatus of claim 1, wherein the testing fixturehas: a ferrite core and at least one capacitive member.
 9. The apparatusof claim 1, wherein the testing fixture comprises windings and a ferritecore to inductively energize the PSUT.
 10. The apparatus of claim 1,wherein the testing fixture comprises: a printed circuit board; twocapacitive plates; an input connector; ground and RF leads from theinput connector to the two capacitive plates; and an insulating guideplate, the insulating guide plate comprising a cavity to receive thePSUT.
 11. The apparatus of claim 1, further comprising a tomographyplate connected to the transmission chain as an illumination source. 12.The apparatus of claim 1, further comprising a tomography plateconnected to the receiving chain as an additional antenna source. 13.The apparatus of claim 1, wherein the analysis unit is configured toassess at least one of an authenticity, a remaining useful life (RUL),and a reliability of the PSUT.
 14. The apparatus of claim 1, wherein thereceiving chain comprises an inverting amplifier to invert a phase of anemission spectra from the PSUT by 180 degrees.
 15. An apparatus,comprising: a shielded enclosure; a testing fixture positioned within aninterior of the shielded enclosure, the testing fixture at leastincluding: a first layer having a capacitive member, and a second layeradjacent to the first layer with the capacitive member, the second layerhaving a cavity to receive an electronic part specimen under test(PSUT); a receiving antenna positioned within the interior; atransmission chain connected to the testing fixture; a receiving chainconnected to the receiving antenna; and a signature analyzer connectedto the receiving chain.
 16. The apparatus of claim 15, wherein thecapacitive member comprises two capacitive plates with an alternativecurrent (AC) voltage of an opposite phase connected to each capacitiveplate.
 17. An apparatus, comprising: a testing fixture configured toreceive an electronic part specimen under test (PSUT) and energize thePSUT without a direct pin-to-metal electrical contact with the PSUT; ashielded enclosure having an interior and exterior, the testing fixturepositioned within the interior; a receiving antenna positioned withinthe interior; a transmission chain connected to the testing fixture, thetransmission chain at least including a filter to pass a high powersignal to the testing fixture; a receiving chain connected to thereceiving antenna, the receiving chain at least including a filter topass a low power signal; and an analysis unit connected to the receivingchain to analyze the low power signal, wherein the testing fixturecomprises: a printed circuit board; two capacitive plates; in inputconnector; ground and RF leads from the input connector to the twocapacitive plates; and an insulating guide plate, the insulating guideplate comprising a cavity to receive the PSUT.